3Agency for Toxic Substances and Disease Registry, Atlanta, Georgia, USA; 4Guy’s and St Thomas’ NHS Foundation Trust and King’s

Overview

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Key numbers

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tigate risk factors for child mortality, and identify children < 5 years of age in need of emergency 0.6% of the global burden of disease and
Results: We surveyed 119 family compounds. Of 463 children < 5 years of age, 118 (25%) had ties or areas where lead batteries are reclaimed
died in the previous year. We tested 59% (204/345) of children < 5 years of age, and all were lead (Brown et al. 2010; Garcia Vargas et al. 2001;
poisoned (≥ 10 µg/dL); 97% (198/204) of children had blood lead levels (BLLs) ≥ 45 µg/dL, the Kaul et al. 1999; Lalor et al. 2006). However,
age with elevated BLLs (97%, > 45 µg/dL), and incidence of convulsions among children before Description of the outbreak. During
death (82%) suggest that most of the recent childhood deaths in the two surveyed villages were meningitis surveillance activities conducted
ceptible to lead exposure because of behav- U.S. cities from 1931 and 1940, with 25% of Health, Zamfara Ministry of Health, Gabriele
with BLLs as low as 70 µg/dL (Centers for 1970 found the mean BLL for children with Global Disease Detection Program, CDC Nigeria,
almost entirely on children < 5 years of age. (separating); and f) using heat to vaporize total blood mercury 0.33 µg/L, and manganese
Young children are most susceptible to lead mercury from the gold mixture after amal- 0.8 µg/L. Precision was evaluated by moni-
with the Declaration of Helsinki developed the compounds and provided parents with QC, with a mean of 7.983, has a CV of 4.8%,
by the World Medical Association (2008). blood lead test results of their children as well whereas the high-level QC with a mean of
After obtaining consent of village leaders, as information on chelation therapy and the 14.929 has a CV of 6.7%. Accuracy for blood
Although there is no blood level of concern for 15 ppb for drinking water was the reference mental contamination) within the compound.
blood mercury levels < 1.0 µg/L (Agency for household survey, blood lead results, and the Hosmer–Lemeshow goodness-of-fit assess-
Investigators used the reference range of into Epi-Info version 3.5.1 (CDC, Atlanta, the outcome were considered. Variables from
7.7–12.1 µg/L from Tietz Textbook of Clinical GA, USA). Statistical analyses were per- bivariate analysis with a p-value < 0.1 were
were targeted for environmental sampling compared with the United Nations High in the survey (n = 119). Responses from one
analyzed for lead content using a portable, cates deteriorating conditions in a refugee < 5 years of age living in the sampled areas of
areas of high contamination (U.S. EPA 2007). villages (NPC and ICF Macro 2009). cally (Table 1). An average of 4.2 children
ment and analysis was given to areas poten- sion was used to identify risk factors for child From May 2009 to May 2010, 25% (118 of
40 ppm, whereas the upper reporting limit children < 5 years of age were excluded from and 82% (97 of 118) were reported to have
was 100,000 ppm. Samples of processed ore bivariate and multivariate analyses. Risk fac- had convulsions before death. A history of
were also collected and analyzed for lead using tors were grouped into demographic, ore pro- convulsions was reported in 17% (58 of 345)
XRF. After XRF analysis, a subset of soil and cessing, and other environmental risk factors. of the surviving children. Sixty-two (53%)
Table 1. Demographics of participating family compounds by village.
containing total lead ≥ 400 ppm in a child’s
401–1,200 ppm, and > 1,200 ppm. A lim- compounds, as of May 2009
was drawn up in a bucket, and the sampling 12 months before survey (%)
bottle was immediately submerged to obtain No. of compounds with ≥ 1 pregnant women (%) 26 (49) 24 (37) 50 (42)
1. was 255 per 1,000 live births. comparison, the geometric mean value for by the villagers was rich in lead content.
Overall, 71% (84 of 118) of compounds total blood mercury reported for children Bivariate and multivariate analyses.
reported processing gold ore within their com- 1–5 years of age in the Fourth National Table 4 summarizes the results of bivariate
pound (Table 2). Compounds participating Report on Human Exposure to Environmental analyses. Children who died were more likely
in ore processing averaged four different pro- Chemicals was 0.33 µg/L (95% confidence than children who survived to have had a
more frequently in compounds in village A centile measuring 1.8 µg/L (95% CI: 1.3, activities (odds ratio (OR) = 1.9; 95% CI:
than in village B (69% vs. 49%, p = 0.002). 2.5) (CDC 2009). Mean blood manganese 1.2, 2.9). Having a mother who participated
Only 25 compounds reported grinding activi- levels were 14.0 (range 4.0–39.0 µg/L) and in grinding, washing, drying, separating, or
ties within their compound (Table 2), but 20.9 (range 4.9–40.8 µg/L) in villages A and melting activities was significantly associ-
compound. Fifty-six of the 84 (67%) com- Environmental sampling. Soil obtained compound (OR = 2.0; 95% CI: 1.3, 3.2).
12 months preceding the investigation (May in the field. Soil lead concentrations ranged not significantly associated with mortality in
2009–May 2010); however, some compounds from 45 ppm to > 100,000 ppm; 85% of bivariate analysis.

Methods (brief)

lages, collected blood from children 2–59 months of age, and obtained soil samples from family ally (WHO 2010). During the past 20 years,
that all four villages participated in artisa- samples was obtained from the head of the pound in village B within time constraints.
nal gold ore–processing activities, and heavy- household before survey initiation. Local health Samples of manufacturer lots of materials
source of the illnesses. Venous blood samples, 4‑hr session on survey administration, venous by CDC laboratories and determined to be
analyzed in Europe, from eight symptomatic blood drawing, and environmental sampling. free of lead. To prevent sample contamina-
BLLs between 168 and 370 µg/dL. These dwellings separated by low walls. Investigators plastic gallon-size storage bags before sample
authorities of the results, and a team of inter- were eligible to participate in the survey. 3-mL blood sample was collected in a lab-
assembled representatives from federal, state, The survey collected information about chil- and Zink 2007).
and international organizations, including the dren < 5 years of age in each compound, includ- A second blood sample was collected from
to stop the increasing rate of child fatalities c) washing ground ore powder with water to reaction cell plasma mass spectrometry was
interview parents, sample blood from children lected from children 2 months to 5 years of Institute of Standards and Technology
accuracy was verified by participating in pro- blanks were taken. Water samples were sent risk factors included proximity to ore-grinding
Toxic Substances and Disease Registry 1999). environmental sample results were entered ment, and the effect of each risk factor on
in each surveyed compound. Samples of Commissioner for Refugees (UNHCR) compound in village A were excluded because
analyzed for lead content using a portable, cates deteriorating conditions in a refugee < 5 years of age living in the sampled areas of
was 100,000 ppm. Samples of processed ore bivariate and multivariate analyses. Risk fac- had convulsions before death. A history of
were also collected and analyzed for lead using tors were grouped into demographic, ore pro- convulsions was reported in 17% (58 of 345)
ore samples was sent to the U.S. Geological Demographic risk factors included age, sex, of 110 surveyed compounds with children

Implications

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Update history

The five most recent substantive edits to this page, classified major (evidence or structure moved), correction (a published value or statement was wrong and has been fixed), or minor (narrative rewritten without changing the underlying evidence). Each description is derived from what the edit did to this page; the linked commit is the authoritative record, routine regeneration passes are excluded, and the full version history lives in git. When DOI minting comes online (see schema docs), each entry below will also link to a version-pinned DataCite DOI.

Commit	Date	Change	Description
b01ec52c	2026-08-04	major	2 sections added
d49e450f	2026-08-03	major	5 sections added; narrative text revised